Abstract: Disclosed is a nano-fiber spinning apparatus using centrifugal force which includes: (i) a top plate 6c which has nano-fiber spinning holes h, and is slantly formed at an inclination angle ? with a virtual horizontal line connecting top of a side wall 6b in a disk shape; (ii) a bottom plate 6a having a curved surface which is concaved and inclined upwardly in a dish shape; and (iii) the cylindrical side wall 6b connecting the top plate 6c and the bottom plate 6a, so as to be wholly formed in a spin-top shape. Also, disclosed is a method of manufacturing nano-fibers which includes, after supplying a spinning dope to the above nano-fiber spinning apparatus 6, spinning nano-fibers with centrifugal force toward a collector 7 provided above the apparatus while generating an air flow toward the collector by an air generator provided below the nano-fiber spinning apparatus 6.

Abstract: Provided is a preparing method of a nano hydroxyapatite/poly(lactic acid) hybrid nanocomposite membrane mat including: mixing a hydroxyapatite powder with poly(lactic acid) in a solvent; and preparing a hydroxyapatite/poly(lactic acid) composite mat on a substrate by nozzle-injecting the mixture obtained in the mixing by an air-jet spinning method.

Abstract: A system and method for controlling voltage at a point of common coupling of a wind farm including a plurality of wind turbines is provided. The method includes: calculating a first voltage error value, which is a difference between a reference voltage value of the point of common coupling and an actual voltage value of the point of common coupling; calculating a compensation reference voltage value based on the first voltage error value; calculating a second voltage error value by subtracting a voltage value of an output terminal of a wind turbine from a sum of a reference voltage value of the wind turbine and the compensation reference voltage value; calculating a reactive power compensation value corresponding to the second voltage error value; and injecting a reactive current corresponding to the reactive current compensation value into a power grid.

Abstract: The present invention relates to a pharmaceutical composition for promoting fertilization comprising cyclic ADP-ribose or its derivative, CD38 and to a method of promoting fertilization by promoting the synthesis of cyclic ADP-ribose to increase sperm motility. Also, the present invention relates to a pharmaceutical composition for contraception and a method for inhibiting fertilization, which can inhibit the expression or function of cyclic ADP-ribose to reduce sperm motility, thereby inhibiting fertilization.

Abstract: Provided is a fiber-optic sensor device. The fiber-optic sensor device is capable of sensing a change in physical quantity by using two fiber Bragg grating units arranged within an optical fiber and a fiber-optic sensor unit arranged therebetween, thereby implementing a low cost fiber-optic grating sensor having a simple structure without requiring a reference FBG.

Abstract: A high-efficiency heterojunction filed effect transistor in which a gate electrode area is formed to the direction of a drain electrode on nitride-based buffer layers with a low dislocation density to exhibit a high breakdown voltage, and its preparation method. The heterojunction field effect transistor according to the present invention minimizes dislocations in a device and provides a high breakdown voltage by forming a gate electrode area to the direction of a drain electrode on the top of the wing area that is on the far side opposite to one that includes the coalescence boundary of the wing area with a lower dislocation density in the buffer layer.

Abstract: A signal transformation apparatus, a signal transformation method, and a recording medium are provided. The signal transformation apparatus selects any one of DCT-II, DST-II, DFT, and HWT, and transforms and outputs the input signal according to the selected transform. Therefore, the hybrid architecture of low complexity can be attained.

Abstract: A dynamic postural balance training system includes a base frame, a support frame which extends upwards from the base frame, a roll motion frame which is coupled to the upper portion of the support frame by a first shaft so as to be rotatable to the left or the right, and a pitch motion frame which is coupled to the roll motion frame by a second shaft so as to be rotatable forwards or rearwards. The system also includes a pelvis fastening unit which is disposed inside the pitch motion frame and which expands to fix the pelvis of the user in place, a connector which extends downwards from the pitch motion frame, and a foot fastening unit which is coupled to the lower end of the connector and expands to fix the feet of the user in place.

Abstract: An inspection apparatus for detecting a defect of a substrate is provided. The inspection apparatus includes a liquid crystal modulator, a light emitting unit, a beam splitter, and a measurement unit. The liquid crystal modulator includes a reflection layer, a liquid crystal layer, an electrode, and a polarizer. The reflection layer reflects a light. The sensor layer includes a hybrid aligned nematic liquid crystal. The electrode is provided on the liquid crystal layer. The polarizer is provided on the electrode.

Abstract: An exemplary embodiment of the present invention provides a three-dimensional virtual liver surgery planning system including: a digital imaging and communications in medicine (DICOM) receiving module which receives an abdomen computer tomography (CT) volume data set from a picture archiving and communication system (PACS) server; a DICOM loading and noise removing module which loads the received abdomen CT volume data set and remove noises; a standard liver volume estimation module which estimates a standard liver volume (SLV) from the denoised abdomen CT volume data set; a liver extraction module which extracts a three-dimensional liver region; a vessel extraction module which extracts a three-dimensional vessel region including a portal vein, a hepatic artery, a hepatic vein, and an inferior vena cava (IVC); a tumor extraction module which extracts a three-dimensional tumor region; a liver segmentation module which divides the extracted three-dimensional liver region into several segments using landmarks w

Abstract: A carbon black sheet with a thin layer of metal nanoparticles is provided by pulse electroplating, which allows metal nanoparticles such as platinum to be uniformly dispersed on a carbon black layer and is very thin, enhancing the efficiency of a metal catalyst such as platinum. The process is also used to form a polymer membrane electrode assembly (MEA) for a fuel cell.

Abstract: The present invention relates to the preparation of poly(amino oxalate) (PAOX) using oxalyl chloride, 1,4-cyclohexanedimethanol, and piperazinediethanol, the preparation of biodegradable polymer particles using the PAOX, and the use of PAOX particles as a drug delivery vehicle. The PAOX according to the present invention is a polymer that has three characteristics of biodegradability, biocompatibility, and cationic properties at the same time with appropriate hydrophobicity and thus can be prepared as particles that allow rapid drug release. Moreover, the particles improve the delivery efficiency of a drug into cells and thus can be efficiently used as a drug delivery vehicle for the treatment of acute inflammatory diseases such as acute liver failure and acute lung injury.

Abstract: A time variant droop-based inertial control method of a wind generator includes the steps of acquiring a nominal frequency value and a system frequency value of a power system; calculating a difference between the system frequency value and the nominal frequency value; calculating a rate of change of the system frequency; acquiring a droop coefficient Rvariant using the rate of change of the system frequency; and controlling the wind generator based on the difference between the system frequency value and the nominal frequency value and the droop coefficient Rvariant.

Abstract: The present invention relates to a method of controlling a wind farm. A method of controlling inertia in a wind farm includes obtaining information about the frequency of an electrical grid which has been received from the electrical grid or calculated using the voltage of the wind turbine, receiving information about the rotor speed of the wind turbine, calculating the kinetic energy of the wind turbine using the information about the rotor speed, calculating an individual droop coefficient of the wind turbine using the calculated kinetic energy, and controlling the wind turbine using the calculated droop coefficient.

Abstract: The present invention relates to a surface-modified biomass which is crosslinked with an amine group-containing cationic polymer on the surface of a cell biomass, its preparation method, and a method for recovering valuable metals using the same. The surface-modified biomass of the present invention has an advantage of improving adsorption of and affinity with anionic pollutants as a result of further introducing a cationic functional group by crosslinking of the amine group-containing cationic polymer on the surface of the biomass. In addition, the method for recovering valuable metals with the present invention is environment-friendly, economical, and harmless to the human body.

Abstract: A flyback type snubber circuit includes an transformer configured to have a primary side connected between a power source and a switch and have a secondary side connected to a diode. The diode is connected between the power source and the transformer.

Abstract: Provided is a fiber-optic sensor device. The fiber-optic sensor device is capable of sensing a change in physical quantity by using two fiber Bragg grating units arranged within an optical fiber and a fiber-optic sensor unit arranged therebetween, thereby implementing a low cost fiber-optic grating sensor having a simple structure without requiring a reference FBG.

Abstract: A signal processing technology for allowing a repeater to transmit a signal received from an external apparatus to a terminal is provided. In a satellite system, a signal transmitted from a satellite or transmitted to a satellite is subject to a low order modulation, and a terrestrial repeater performs a high order modulation on signals and retransmits the signals.

Abstract: It is well known that relay-based DF cooperative wireless networks outperform AF cooperative networks. However, this performance enhancement is achievable through considerable signal processing (precoding/decoding) at relay nodes. To reduce the precoding/decoding complexity, a method for precoding and decoding a distributive MIMO channel in the relay-based DF cooperative wireless network using EVD based on properties of Jacket transformations is provided.

Abstract: A high efficiency DC/DC converter with high conversion ratio is provided. The DC/DC converter includes a power switch for selectively switching an electrical connection between one side of a power supply and anodes of a first diode and a second diode, a first capacitive element whose one side is connected to a cathode of the first diode, a second capacitive element whose one side is connected to a cathode of the second diode, a first-first switch for selectively switching an electrical connection between the other side of the first capacitive element and the other side of the power supply, and a second-first switch for selectively switching an electrical connection between the other side of the first capacitive element and one side of the second capacitive element.